diff --git a/lib/spack/spack/caches.py b/lib/spack/spack/caches.py
index bdece50421..a7910905bc 100644
--- a/lib/spack/spack/caches.py
+++ b/lib/spack/spack/caches.py
@@ -53,20 +53,23 @@ class MirrorCache(object):
     def __init__(self, root):
         self.root = os.path.abspath(root)
 
-    def store(self, fetcher, relative_dest, cosmetic_path=None):
+    def store(self, fetcher, relative_dest):
+        """Fetch and relocate the fetcher's target into our mirror cache."""
+
         # Note this will archive package sources even if they would not
         # normally be cached (e.g. the current tip of an hg/git branch)
         dst = os.path.join(self.root, relative_dest)
         mkdirp(os.path.dirname(dst))
         fetcher.archive(dst)
 
-        # Add a symlink path that a human can read to understand what resource
-        # the archive path refers to
-        if not cosmetic_path:
-            return
-        cosmetic_path = os.path.join(self.root, cosmetic_path)
+    def symlink(self, mirror_ref):
+        """Symlink a human readible path in our mirror to the actual
+        storage location."""
+
+        cosmetic_path = os.path.join(self.root, mirror_ref.cosmetic_path)
         relative_dst = os.path.relpath(
-            dst, start=os.path.dirname(cosmetic_path))
+            mirror_ref.storage_path,
+            start=os.path.dirname(cosmetic_path))
         if not os.path.exists(cosmetic_path):
             mkdirp(os.path.dirname(cosmetic_path))
             os.symlink(relative_dst, cosmetic_path)
diff --git a/lib/spack/spack/mirror.py b/lib/spack/spack/mirror.py
index f7e8e73ea9..db32ceb5a5 100644
--- a/lib/spack/spack/mirror.py
+++ b/lib/spack/spack/mirror.py
@@ -519,7 +519,7 @@ def add_single_spec(spec, mirror_root, mirror_stats):
         else:
             tty.warn(
                 "Error while fetching %s" % spec.cformat('{name}{@version}'),
-                exception.message)
+                getattr(exception, 'message', exception))
         mirror_stats.error()
 
 
diff --git a/lib/spack/spack/patch.py b/lib/spack/spack/patch.py
index 79550538db..ba8d4c5ef8 100644
--- a/lib/spack/spack/patch.py
+++ b/lib/spack/spack/patch.py
@@ -199,11 +199,15 @@ def fetch(self, stage):
         fetcher = fs.URLFetchStrategy(self.url, fetch_digest,
                                       expand=bool(self.archive_sha256))
 
-        per_package_ref = os.path.join(
-            self.owner.split('.')[-1], os.path.basename(self.url))
+        # The same package can have multiple patches with the same name but
+        # with different contents, therefore apply a subset of the hash.
+        name = '{0}-{1}'.format(os.path.basename(self.url), fetch_digest[:7])
+
+        per_package_ref = os.path.join(self.owner.split('.')[-1], name)
         # Reference starting with "spack." is required to avoid cyclic imports
         mirror_ref = spack.mirror.mirror_archive_paths(
-            fetcher, per_package_ref)
+            fetcher,
+            per_package_ref)
 
         self.stage = spack.stage.Stage(fetcher, mirror_paths=mirror_ref)
         self.stage.create()
diff --git a/lib/spack/spack/stage.py b/lib/spack/spack/stage.py
index d2dd3e6e7a..e46354d963 100644
--- a/lib/spack/spack/stage.py
+++ b/lib/spack/spack/stage.py
@@ -498,13 +498,13 @@ def cache_mirror(self, stats):
 
         if os.path.exists(absolute_storage_path):
             stats.already_existed(absolute_storage_path)
-            return
+        else:
+            self.fetch()
+            spack.caches.mirror_cache.store(
+                self.fetcher, self.mirror_paths.storage_path)
+            stats.added(absolute_storage_path)
 
-        self.fetch()
-        spack.caches.mirror_cache.store(
-            self.fetcher, self.mirror_paths.storage_path,
-            self.mirror_paths.cosmetic_path)
-        stats.added(absolute_storage_path)
+        spack.caches.mirror_cache.symlink(self.mirror_paths)
 
     def expand_archive(self):
         """Changes to the stage directory and attempt to expand the downloaded